<?php

    /**
     *    PHPExcel_Cell
     *    Copyright (c) 2006 - 2015 PHPExcel
     *    This library is free software; you can redistribute it and/or
     *    modify it under the terms of the GNU Lesser General Public
     *    License as published by the Free Software Foundation; either
     *    version 2.1 of the License, or (at your option) any later version.
     *    This library is distributed in the hope that it will be useful,
     *    but WITHOUT ANY WARRANTY; without even the implied warranty of
     *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     *    Lesser General Public License for more details.
     *    You should have received a copy of the GNU Lesser General Public
     *    License along with this library; if not, write to the Free Software
     *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category     PHPExcel
     * @package      PHPExcel_Cell
     * @copyright    Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license      http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version      ##VERSION##, ##DATE##
     */
    class PHPExcel_Cell {
        /**
         *  Default range variable constant
         * @var  string
         */
        const DEFAULT_RANGE = 'A1:A1';
        /**
         *    Value binder to use
         * @var    PHPExcel_Cell_IValueBinder
         */
        private static $valueBinder;
        /**
         *    Value of the cell
         * @var    mixed
         */
        private $value;
        /**
         *    Calculated value of the cell (used for caching)
         *    This returns the value last calculated by MS Excel or whichever spreadsheet program was used to
         *        create the original spreadsheet file.
         *    Note that this value is not guaranteed to reflect the actual calculated value because it is
         *        possible that auto-calculation was disabled in the original spreadsheet, and underlying data
         *        values used by the formula have changed since it was last calculated.
         * @var mixed
         */
        private $calculatedValue;
        /**
         *    Type of the cell data
         * @var    string
         */
        private $dataType;
        /**
         *    Parent worksheet
         * @var    PHPExcel_CachedObjectStorage_CacheBase
         */
        private $parent;
        /**
         *    Index to cellXf
         * @var    int
         */
        private $xfIndex = 0;
        /**
         *    Attributes of the formula
         */
        private $formulaAttributes;

        /**
         *    Create a new Cell
         * @param    mixed              $pValue
         * @param    string             $pDataType
         * @param    PHPExcel_Worksheet $pSheet
         * @throws    PHPExcel_Exception
         */
        public function __construct($pValue = null, $pDataType = null, PHPExcel_Worksheet $pSheet = null) {
            // Initialise cell value
            $this->value = $pValue;
            // Set worksheet cache
            $this->parent = $pSheet->getCellCacheController();
            // Set datatype?
            if ($pDataType !== null) {
                if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2) {
                    $pDataType = PHPExcel_Cell_DataType::TYPE_STRING;
                }
                $this->dataType = $pDataType;
            } elseif (!self::getValueBinder()->bindValue($this, $pValue)) {
                throw new PHPExcel_Exception("Value could not be bound to cell.");
            }
        }

        /**
         * Get value binder to use
         * @return PHPExcel_Cell_IValueBinder
         */
        public static function getValueBinder() {
            if (self::$valueBinder === null) {
                self::$valueBinder = new PHPExcel_Cell_DefaultValueBinder();
            }
            return self::$valueBinder;
        }

        /**
         * Set value binder to use
         * @param PHPExcel_Cell_IValueBinder $binder
         * @throws PHPExcel_Exception
         */
        public static function setValueBinder(PHPExcel_Cell_IValueBinder $binder = null) {
            if ($binder === null) {
                throw new PHPExcel_Exception("A PHPExcel_Cell_IValueBinder is required for PHPExcel to function correctly.");
            }
            self::$valueBinder = $binder;
        }

        /**
         *    Make string row, column or cell coordinate absolute
         * @param    string $pCoordinateString e.g. 'A' or '1' or 'A1'
         *                                     Note that this value can be a row or column reference as well as a cell reference
         * @return    string    Absolute coordinate        e.g. '$A' or '$1' or '$A$1'
         * @throws    PHPExcel_Exception
         */
        public static function absoluteReference($pCoordinateString = 'A1') {
            if (strpos($pCoordinateString, ':') === false && strpos($pCoordinateString, ',') === false) {
                // Split out any worksheet name from the reference
                $worksheet   = '';
                $cellAddress = explode('!', $pCoordinateString);
                if (count($cellAddress) > 1) {
                    list($worksheet, $pCoordinateString) = $cellAddress;
                }
                if ($worksheet > '') {
                    $worksheet .= '!';
                }
                // Create absolute coordinate
                if (ctype_digit($pCoordinateString)) {
                    return $worksheet . '$' . $pCoordinateString;
                } elseif (ctype_alpha($pCoordinateString)) {
                    return $worksheet . '$' . strtoupper($pCoordinateString);
                }
                return $worksheet . self::absoluteCoordinate($pCoordinateString);
            }
            throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
        }

        /**
         *    Make string coordinate absolute
         * @param    string $pCoordinateString e.g. 'A1'
         * @return    string    Absolute coordinate        e.g. '$A$1'
         * @throws    PHPExcel_Exception
         */
        public static function absoluteCoordinate($pCoordinateString = 'A1') {
            if (strpos($pCoordinateString, ':') === false && strpos($pCoordinateString, ',') === false) {
                // Split out any worksheet name from the coordinate
                $worksheet   = '';
                $cellAddress = explode('!', $pCoordinateString);
                if (count($cellAddress) > 1) {
                    list($worksheet, $pCoordinateString) = $cellAddress;
                }
                if ($worksheet > '') {
                    $worksheet .= '!';
                }
                // Create absolute coordinate
                list($column, $row) = self::coordinateFromString($pCoordinateString);
                $column = ltrim($column, '$');
                $row    = ltrim($row, '$');
                return $worksheet . '$' . $column . '$' . $row;
            }
            throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
        }

        /**
         *    Build range from coordinate strings
         * @param    array $pRange Array containg one or more arrays containing one or two coordinate strings
         * @return    string    String representation of $pRange
         * @throws    PHPExcel_Exception
         */
        public static function buildRange($pRange) {
            // Verify range
            if (!is_array($pRange) || empty($pRange) || !is_array($pRange[0])) {
                throw new PHPExcel_Exception('Range does not contain any information');
            }
            // Build range
            $imploded = [];
            $counter  = count($pRange);
            for ($i = 0; $i < $counter; ++$i) {
                $pRange[$i] = implode(':', $pRange[$i]);
            }
            $imploded = implode(',', $pRange);
            return $imploded;
        }

        /**
         *    Calculate range dimension
         * @param    string $pRange Cell range (e.g. A1:A1)
         * @return    array    Range dimension (width, height)
         */
        public static function rangeDimension($pRange = 'A1:A1') {
            // Calculate range outer borders
            list($rangeStart, $rangeEnd) = self::rangeBoundaries($pRange);
            return [
                ($rangeEnd[0] - $rangeStart[0] + 1),
                ($rangeEnd[1] - $rangeStart[1] + 1)
            ];
        }

        /**
         *    Calculate range boundaries
         * @param    string $pRange Cell range (e.g. A1:A1)
         * @return    array    Range coordinates array(Start Cell, End Cell)
         *                          where Start Cell and End Cell are arrays (Column ID, Row Number)
         */
        public static function getRangeBoundaries($pRange = 'A1:A1') {
            // Ensure $pRange is a valid range
            if (empty($pRange)) {
                $pRange = self::DEFAULT_RANGE;
            }
            // Uppercase coordinate
            $pRange = strtoupper($pRange);
            // Extract range
            if (strpos($pRange, ':') === false) {
                $rangeA = $rangeB = $pRange;
            } else {
                list($rangeA, $rangeB) = explode(':', $pRange);
            }
            return [
                self::coordinateFromString($rangeA),
                self::coordinateFromString($rangeB)
            ];
        }

        /**
         *    String from columnindex
         * @param    int $pColumnIndex Column index (base 0 !!!)
         * @return    string
         */
        public static function stringFromColumnIndex($pColumnIndex = 0) {
            //    Using a lookup cache adds a slight memory overhead, but boosts speed
            //    caching using a static within the method is faster than a class static,
            //        though it's additional memory overhead
            static $_indexCache = [];
            if (!isset($_indexCache[$pColumnIndex])) {
                // Determine column string
                if ($pColumnIndex < 26) {
                    $_indexCache[$pColumnIndex] = chr(65 + $pColumnIndex);
                } elseif ($pColumnIndex < 702) {
                    $_indexCache[$pColumnIndex] = chr(64 + ($pColumnIndex / 26)) . chr(65 + $pColumnIndex % 26);
                } else {
                    $_indexCache[$pColumnIndex] = chr(64 + (($pColumnIndex - 26) / 676)) . chr(65 + ((($pColumnIndex - 26) % 676) / 26)) . chr(65 + $pColumnIndex % 26);
                }
            }
            return $_indexCache[$pColumnIndex];
        }

        /**
         *    Extract all cell references in range
         * @param    string $pRange Range (e.g. A1 or A1:C10 or A1:E10 A20:E25)
         * @return    array    Array containing single cell references
         */
        public static function extractAllCellReferencesInRange($pRange = 'A1') {
            // Returnvalue
            $returnValue = [];
            // Explode spaces
            $cellBlocks = explode(' ', str_replace('$', '', strtoupper($pRange)));
            foreach ($cellBlocks as $cellBlock) {
                // Single cell?
                if (strpos($cellBlock, ':') === false && strpos($cellBlock, ',') === false) {
                    $returnValue[] = $cellBlock;
                    continue;
                }
                // Range...
                $ranges = self::splitRange($cellBlock);
                foreach ($ranges as $range) {
                    // Single cell?
                    if (!isset($range[1])) {
                        $returnValue[] = $range[0];
                        continue;
                    }
                    // Range...
                    list($rangeStart, $rangeEnd) = $range;
                    sscanf($rangeStart, '%[A-Z]%d', $startCol, $startRow);
                    sscanf($rangeEnd, '%[A-Z]%d', $endCol, $endRow);
                    ++$endCol;
                    // Current data
                    $currentCol = $startCol;
                    $currentRow = $startRow;
                    // Loop cells
                    while ($currentCol != $endCol) {
                        while ($currentRow <= $endRow) {
                            $returnValue[] = $currentCol . $currentRow;
                            ++$currentRow;
                        }
                        ++$currentCol;
                        $currentRow = $startRow;
                    }
                }
            }
            //    Sort the result by column and row
            $sortKeys = [];
            foreach (array_unique($returnValue) as $coord) {
                sscanf($coord, '%[A-Z]%d', $column, $row);
                $sortKeys[sprintf('%3s%09d', $column, $row)] = $coord;
            }
            ksort($sortKeys);
            // Return value
            return array_values($sortKeys);
        }

        /**
         * Compare 2 cells
         * @param    PHPExcel_Cell $a Cell a
         * @param    PHPExcel_Cell $b Cell b
         * @return    int        Result of comparison (always -1 or 1, never zero!)
         */
        public static function compareCells(PHPExcel_Cell $a, PHPExcel_Cell $b) {
            if ($a->getRow() < $b->getRow()) {
                return -1;
            } elseif ($a->getRow() > $b->getRow()) {
                return 1;
            } elseif (self::columnIndexFromString($a->getColumn()) < self::columnIndexFromString($b->getColumn())) {
                return -1;
            } else {
                return 1;
            }
        }

        public function detach() {
            $this->parent = null;
        }

        public function attach(PHPExcel_CachedObjectStorage_CacheBase $parent) {
            $this->parent = $parent;
        }

        /**
         *    Get cell value with formatting
         * @return    string
         */
        public function getFormattedValue() {
            return (string)PHPExcel_Style_NumberFormat::toFormattedString($this->getCalculatedValue(), $this->getStyle()->getNumberFormat()->getFormatCode()
            );
        }

        /**
         *    Get calculated cell value
         * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
         * @param    boolean $resetLog Whether the calculation engine logger should be reset or not
         * @return    mixed
         * @throws    PHPExcel_Exception
         */
        public function getCalculatedValue($resetLog = true) {
            //echo 'Cell '.$this->getCoordinate().' value is a '.$this->dataType.' with a value of '.$this->getValue().PHP_EOL;
            if ($this->dataType == PHPExcel_Cell_DataType::TYPE_FORMULA) {
                try {
                    //echo 'Cell value for '.$this->getCoordinate().' is a formula: Calculating value'.PHP_EOL;
                    $result = PHPExcel_Calculation::getInstance($this->getWorksheet()->getParent()
                    )->calculateCellValue($this, $resetLog);
                    //echo $this->getCoordinate().' calculation result is '.$result.PHP_EOL;
                    //    We don't yet handle array returns
                    if (is_array($result)) {
                        while (is_array($result)) {
                            $result = array_pop($result);
                        }
                    }
                } catch (PHPExcel_Exception $ex) {
                    if (($ex->getMessage() === 'Unable to access External Workbook') && ($this->calculatedValue !== null)) {
                        //echo 'Returning fallback value of '.$this->calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;
                        return $this->calculatedValue; // Fallback for calculations referencing external files.
                    }
                    //echo 'Calculation Exception: '.$ex->getMessage().PHP_EOL;
                    $result = '#N/A';
                    throw new PHPExcel_Calculation_Exception($this->getWorksheet()->getTitle() . '!' . $this->getCoordinate() . ' -> ' . $ex->getMessage()
                    );
                }
                if ($result === '#Not Yet Implemented') {
                    //echo 'Returning fallback value of '.$this->calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;
                    return $this->calculatedValue; // Fallback if calculation engine does not support the formula.
                }
                //echo 'Returning calculated value of '.$result.' for cell '.$this->getCoordinate().PHP_EOL;
                return $result;
            } elseif ($this->value instanceof PHPExcel_RichText) {
                //        echo 'Cell value for '.$this->getCoordinate().' is rich text: Returning data value of '.$this->value.'<br />';
                return $this->value->getPlainText();
            }
            //        echo 'Cell value for '.$this->getCoordinate().' is not a formula: Returning data value of '.$this->value.'<br />';
            return $this->value;
        }

        /**
         *    Set old calculated value (cached)
         * @param    mixed $pValue Value
         * @return    PHPExcel_Cell
         */
        public function setCalculatedValue($pValue = null) {
            if ($pValue !== null) {
                $this->calculatedValue = (is_numeric($pValue)) ? (float)$pValue : $pValue;
            }
            return $this->notifyCacheController();
        }

        /**
         *    Get parent worksheet
         * @return PHPExcel_Worksheet
         */
        public function getWorksheet() {
            return $this->parent->getParent();
        }

        /**
         *    Get cell coordinate
         * @return    string
         */
        public function getCoordinate() {
            return $this->parent->getCurrentAddress();
        }

        /**
         *    Get cell style
         * @return    PHPExcel_Style
         */
        public function getStyle() {
            return $this->getWorksheet()->getStyle($this->getCoordinate());
        }

        /**
         *    Set the value for a cell, with the explicit data type passed to the method (bypassing any use of the value binder)
         * @param    mixed  $pValue    Value
         * @param    string $pDataType Explicit data type
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function setValueExplicit($pValue = null, $pDataType = PHPExcel_Cell_DataType::TYPE_STRING) {
            // set the value according to data type
            switch ($pDataType) {
                case PHPExcel_Cell_DataType::TYPE_NULL:
                    $this->value = $pValue;
                    break;
                case PHPExcel_Cell_DataType::TYPE_STRING2:
                    $pDataType = PHPExcel_Cell_DataType::TYPE_STRING;
                // no break
                case PHPExcel_Cell_DataType::TYPE_STRING:
                    // Synonym for string
                case PHPExcel_Cell_DataType::TYPE_INLINE:
                    // Rich text
                    $this->value = PHPExcel_Cell_DataType::checkString($pValue);
                    break;
                case PHPExcel_Cell_DataType::TYPE_NUMERIC:
                    $this->value = (float)$pValue;
                    break;
                case PHPExcel_Cell_DataType::TYPE_FORMULA:
                    $this->value = (string)$pValue;
                    break;
                case PHPExcel_Cell_DataType::TYPE_BOOL:
                    $this->value = (bool)$pValue;
                    break;
                case PHPExcel_Cell_DataType::TYPE_ERROR:
                    $this->value = PHPExcel_Cell_DataType::checkErrorCode($pValue);
                    break;
                default:
                    throw new PHPExcel_Exception('Invalid datatype: ' . $pDataType);
                    break;
            }
            // set the datatype
            $this->dataType = $pDataType;
            return $this->notifyCacheController();
        }

        /**
         *    Send notification to the cache controller
         * @return void
         **/
        public function notifyCacheController() {
            $this->parent->updateCacheData($this);
            return $this;
        }

        /**
         *    Get old calculated value (cached)
         *    This returns the value last calculated by MS Excel or whichever spreadsheet program was used to
         *        create the original spreadsheet file.
         *    Note that this value is not guaranteed to refelect the actual calculated value because it is
         *        possible that auto-calculation was disabled in the original spreadsheet, and underlying data
         *        values used by the formula have changed since it was last calculated.
         * @return    mixed
         */
        public function getOldCalculatedValue() {
            return $this->calculatedValue;
        }

        /**
         *    Get cell data type
         * @return string
         */
        public function getDataType() {
            return $this->dataType;
        }

        /**
         *    Set cell data type
         * @param    string $pDataType
         * @return    PHPExcel_Cell
         */
        public function setDataType($pDataType = PHPExcel_Cell_DataType::TYPE_STRING) {
            if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2) {
                $pDataType = PHPExcel_Cell_DataType::TYPE_STRING;
            }
            $this->dataType = $pDataType;
            return $this->notifyCacheController();
        }

        /**
         *  Identify if the cell contains a formula
         * @return boolean
         */
        public function isFormula() {
            return $this->dataType == PHPExcel_Cell_DataType::TYPE_FORMULA;
        }

        /**
         *    Does this cell contain Data validation rules?
         * @return    boolean
         * @throws    PHPExcel_Exception
         */
        public function hasDataValidation() {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot check for data validation when cell is not bound to a worksheet');
            }
            return $this->getWorksheet()->dataValidationExists($this->getCoordinate());
        }

        /**
         *    Get Data validation rules
         * @return    PHPExcel_Cell_DataValidation
         * @throws    PHPExcel_Exception
         */
        public function getDataValidation() {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot get data validation for cell that is not bound to a worksheet');
            }
            return $this->getWorksheet()->getDataValidation($this->getCoordinate());
        }

        /**
         *    Set Data validation rules
         * @param    PHPExcel_Cell_DataValidation $pDataValidation
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function setDataValidation(PHPExcel_Cell_DataValidation $pDataValidation = null) {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot set data validation for cell that is not bound to a worksheet');
            }
            $this->getWorksheet()->setDataValidation($this->getCoordinate(), $pDataValidation);
            return $this->notifyCacheController();
        }

        /**
         *    Does this cell contain a Hyperlink?
         * @return boolean
         * @throws    PHPExcel_Exception
         */
        public function hasHyperlink() {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot check for hyperlink when cell is not bound to a worksheet');
            }
            return $this->getWorksheet()->hyperlinkExists($this->getCoordinate());
        }

        /**
         *    Get Hyperlink
         * @return    PHPExcel_Cell_Hyperlink
         * @throws    PHPExcel_Exception
         */
        public function getHyperlink() {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot get hyperlink for cell that is not bound to a worksheet');
            }
            return $this->getWorksheet()->getHyperlink($this->getCoordinate());
        }

        /**
         *    Set Hyperlink
         * @param    PHPExcel_Cell_Hyperlink $pHyperlink
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function setHyperlink(PHPExcel_Cell_Hyperlink $pHyperlink = null) {
            if (!isset($this->parent)) {
                throw new PHPExcel_Exception('Cannot set hyperlink for cell that is not bound to a worksheet');
            }
            $this->getWorksheet()->setHyperlink($this->getCoordinate(), $pHyperlink);
            return $this->notifyCacheController();
        }

        /**
         *    Get parent worksheet
         * @return PHPExcel_CachedObjectStorage_CacheBase
         */
        public function getParent() {
            return $this->parent;
        }

        /**
         *    Is this cell in a merge range
         * @return boolean
         */
        public function isInMergeRange() {
            return (boolean)$this->getMergeRange();
        }

        /**
         *    If this cell is in a merge range, then return the range
         * @return string
         */
        public function getMergeRange() {
            foreach ($this->getWorksheet()->getMergeCells() as $mergeRange) {
                if ($this->isInRange($mergeRange)) {
                    return $mergeRange;
                }
            }
            return false;
        }

        /**
         *    Is cell in a specific range?
         * @param    string $pRange Cell range (e.g. A1:A1)
         * @return    boolean
         */
        public function isInRange($pRange = 'A1:A1') {
            list($rangeStart, $rangeEnd) = self::rangeBoundaries($pRange);
            // Translate properties
            $myColumn = self::columnIndexFromString($this->getColumn());
            $myRow    = $this->getRow();
            // Verify if cell is in range
            return (($rangeStart[0] <= $myColumn) && ($rangeEnd[0] >= $myColumn) && ($rangeStart[1] <= $myRow) && ($rangeEnd[1] >= $myRow));
        }

        /**
         *    Calculate range boundaries
         * @param    string $pRange Cell range (e.g. A1:A1)
         * @return    array    Range coordinates array(Start Cell, End Cell)
         *                          where Start Cell and End Cell are arrays (Column Number, Row Number)
         */
        public static function rangeBoundaries($pRange = 'A1:A1') {
            // Ensure $pRange is a valid range
            if (empty($pRange)) {
                $pRange = self::DEFAULT_RANGE;
            }
            // Uppercase coordinate
            $pRange = strtoupper($pRange);
            // Extract range
            if (strpos($pRange, ':') === false) {
                $rangeA = $rangeB = $pRange;
            } else {
                list($rangeA, $rangeB) = explode(':', $pRange);
            }
            // Calculate range outer borders
            $rangeStart = self::coordinateFromString($rangeA);
            $rangeEnd   = self::coordinateFromString($rangeB);
            // Translate column into index
            $rangeStart[0] = self::columnIndexFromString($rangeStart[0]);
            $rangeEnd[0]   = self::columnIndexFromString($rangeEnd[0]);
            return [
                $rangeStart,
                $rangeEnd
            ];
        }

        /**
         *    Coordinate from string
         * @param    string $pCoordinateString
         * @return    array    Array containing column and row (indexes 0 and 1)
         * @throws    PHPExcel_Exception
         */
        public static function coordinateFromString($pCoordinateString = 'A1') {
            if (preg_match("/^([$]?[A-Z]{1,3})([$]?\d{1,7})$/", $pCoordinateString, $matches)) {
                return [
                    $matches[1],
                    $matches[2]
                ];
            } elseif ((strpos($pCoordinateString, ':') !== false) || (strpos($pCoordinateString, ',') !== false)) {
                throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
            } elseif ($pCoordinateString == '') {
                throw new PHPExcel_Exception('Cell coordinate can not be zero-length string');
            }
            throw new PHPExcel_Exception('Invalid cell coordinate ' . $pCoordinateString);
        }

        /**
         *    Column index from string
         * @param    string $pString
         * @return    int Column index (base 1 !!!)
         */
        public static function columnIndexFromString($pString = 'A') {
            //    Using a lookup cache adds a slight memory overhead, but boosts speed
            //    caching using a static within the method is faster than a class static,
            //        though it's additional memory overhead
            static $_indexCache = [];
            if (isset($_indexCache[$pString])) {
                return $_indexCache[$pString];
            }
            //    It's surprising how costly the strtoupper() and ord() calls actually are, so we use a lookup array rather than use ord()
            //        and make it case insensitive to get rid of the strtoupper() as well. Because it's a static, there's no significant
            //        memory overhead either
            static $_columnLookup = [
                'A' => 1,
                'B' => 2,
                'C' => 3,
                'D' => 4,
                'E' => 5,
                'F' => 6,
                'G' => 7,
                'H' => 8,
                'I' => 9,
                'J' => 10,
                'K' => 11,
                'L' => 12,
                'M' => 13,
                'N' => 14,
                'O' => 15,
                'P' => 16,
                'Q' => 17,
                'R' => 18,
                'S' => 19,
                'T' => 20,
                'U' => 21,
                'V' => 22,
                'W' => 23,
                'X' => 24,
                'Y' => 25,
                'Z' => 26,
                'a' => 1,
                'b' => 2,
                'c' => 3,
                'd' => 4,
                'e' => 5,
                'f' => 6,
                'g' => 7,
                'h' => 8,
                'i' => 9,
                'j' => 10,
                'k' => 11,
                'l' => 12,
                'm' => 13,
                'n' => 14,
                'o' => 15,
                'p' => 16,
                'q' => 17,
                'r' => 18,
                's' => 19,
                't' => 20,
                'u' => 21,
                'v' => 22,
                'w' => 23,
                'x' => 24,
                'y' => 25,
                'z' => 26
            ];
            //    We also use the language construct isset() rather than the more costly strlen() function to match the length of $pString
            //        for improved performance
            if (isset($pString{0})) {
                if (!isset($pString{1})) {
                    $_indexCache[$pString] = $_columnLookup[$pString];
                    return $_indexCache[$pString];
                } elseif (!isset($pString{2})) {
                    $_indexCache[$pString] = $_columnLookup[$pString{0}] * 26 + $_columnLookup[$pString{1}];
                    return $_indexCache[$pString];
                } elseif (!isset($pString{3})) {
                    $_indexCache[$pString] = $_columnLookup[$pString{0}] * 676 + $_columnLookup[$pString{1}] * 26 + $_columnLookup[$pString{2}];
                    return $_indexCache[$pString];
                }
            }
            throw new PHPExcel_Exception("Column string index can not be " . ((isset($pString{0})) ? "longer than 3 characters" : "empty"));
        }

        /**
         *    Get cell coordinate column
         * @return    string
         */
        public function getColumn() {
            return $this->parent->getCurrentColumn();
        }

        /**
         *    Get cell coordinate row
         * @return    int
         */
        public function getRow() {
            return $this->parent->getCurrentRow();
        }

        /**
         *    Is this cell the master (top left cell) in a merge range (that holds the actual data value)
         * @return boolean
         */
        public function isMergeRangeValueCell() {
            if ($mergeRange = $this->getMergeRange()) {
                $mergeRange = PHPExcel_Cell::splitRange($mergeRange);
                list($startCell) = $mergeRange[0];
                if ($this->getCoordinate() === $startCell) {
                    return true;
                }
            }
            return false;
        }

        /**
         *    Split range into coordinate strings
         * @param    string $pRange               e.g. 'B4:D9' or 'B4:D9,H2:O11' or 'B4'
         * @return    array    Array containg one or more arrays containing one or two coordinate strings
         *                                        e.g. array('B4','D9') or array(array('B4','D9'),array('H2','O11'))
         *                                        or array('B4')
         */
        public static function splitRange($pRange = 'A1:A1') {
            // Ensure $pRange is a valid range
            if (empty($pRange)) {
                $pRange = self::DEFAULT_RANGE;
            }
            $exploded = explode(',', $pRange);
            $counter  = count($exploded);
            for ($i = 0; $i < $counter; ++$i) {
                $exploded[$i] = explode(':', $exploded[$i]);
            }
            return $exploded;
        }

        /**
         *    Re-bind parent
         * @param    PHPExcel_Worksheet $parent
         * @return    PHPExcel_Cell
         */
        public function rebindParent(PHPExcel_Worksheet $parent) {
            $this->parent = $parent->getCellCacheController();
            return $this->notifyCacheController();
        }

        /**
         * Implement PHP __clone to create a deep clone, not just a shallow copy.
         */
        public function __clone() {
            $vars = get_object_vars($this);
            foreach ($vars as $key => $value) {
                if ((is_object($value)) && ($key != 'parent')) {
                    $this->$key = clone $value;
                } else {
                    $this->$key = $value;
                }
            }
        }

        /**
         * Get index to cellXf
         * @return int
         */
        public function getXfIndex() {
            return $this->xfIndex;
        }

        /**
         * Set index to cellXf
         * @param int $pValue
         * @return PHPExcel_Cell
         */
        public function setXfIndex($pValue = 0) {
            $this->xfIndex = $pValue;
            return $this->notifyCacheController();
        }

        /**
         * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
         */
        public function getFormulaAttributes() {
            return $this->formulaAttributes;
        }

        /**
         * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
         */
        public function setFormulaAttributes($pAttributes) {
            $this->formulaAttributes = $pAttributes;
            return $this;
        }

        /**
         * Convert to string
         * @return string
         */
        public function __toString() {
            return (string)$this->getValue();
        }

        /**
         *    Get cell value
         * @return    mixed
         */
        public function getValue() {
            return $this->value;
        }

        /**
         *    Set cell value
         *    Sets the value for a cell, automatically determining the datatype using the value binder
         * @param    mixed $pValue Value
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function setValue($pValue = null) {
            if (!self::getValueBinder()->bindValue($this, $pValue)) {
                throw new PHPExcel_Exception("Value could not be bound to cell.");
            }
            return $this;
        }
    }
